1. Field of the Invention
The present invention relates to an aluminum alloy excellent in mechanical properties such as high-temperature strength, ductility, impact strength and tensile strength.
2. Description of the Prior Art
Aluminum alloys known hitherto include, for example, Alxe2x80x94Cu, Alxe2x80x94Si, Alxe2x80x94Mg, Alxe2x80x94Cuxe2x80x94Si, Alxe2x80x94Cuxe2x80x94Mg and Alxe2x80x94Znxe2x80x94Mg alloys. They are widely used as members of aircrafts, vehicles, seacrafts, etc., exterior materials, sashes, roof materials, etc. for buildings, members of marine equipment, or members of nuclear reactors depending on the characteristic properties thereof. However, the hardness and thermal resistance of these aluminum alloys are generally insufficient. Under these circumstances, it has been attempted recently to solidify an aluminum alloy material by quenching in order to make the structure thereof fine and also to improve the mechanical properties such as strength thereof and chemical properties such as corrosion resistance (refer to Japanese Patent Laid-Open Nos. 275732/1989, 256875/1994 and 199317/1996). Although these materials are excellent in strength and thermal resistance, they still have room for improvement in ductility and formability so as to improve the practical use thereof.
The present invention has been completed after intensive investigations made under the above-described circumstances. An object of the present invention is to provide an aluminum alloy excellent in strength, hardness, ductility and formability and having a high specific strength by forming a structure comprising quasi-crystals or crystals close to them which are finely dispersed in an aluminum matrix having a specified composition.
The present invention provides a high-strength, high-ductility aluminum alloy having a composition represented by the general formula:
AlbalCuaMb or AlbalCuaMbTMc
wherein M represents one or two elements selected between Mn and Cr; TM represents at least one element selected from the group consisting of Ti, V, Fe, Co, Ni and Zr; and a, b and c each represent an atomic percentage of 0 less than axe2x89xa63, 2 less than bxe2x89xa65 and 0 less than cxe2x89xa62, and containing quasi-crystals in the structure thereof.